phenylmethylsulfonyl fluoride (ST506, Beyotime Institute of Biotechnology).
Proteins were quantified using the BCA Protein Assay Kit (P0010, Beyotime
Institute of Biotechnology). Total protein (30 μg) was loaded onto
SDS–polyacrylamide gel electrophoresis gels and subsequently transferred
to poly(vinylidene fluoride) membranes (162-0177, Bio-Rad). After blocking with
5% nonfat milk in PBST (phosphate-buffered saline with Tween 20), membranes were
incubated with the following primary antibodies at the suggested dilutions:
anti-CDKN1A/p21 (10355-1-AP, ProteinTech Group), anti-CDKN2A/p16 (10883-1-AP,
ProteinTech Group), anti-ACTB (AA128, Beyotime Institute of Biotechnology), and
anti-ETS1 antibody (14069S, Cell Signaling Technology). Primary antibodies were
detected with horseradish peroxidase–labeled goat anti-rabbit (A0208,
Beyotime Institute of Biotechnology) or anti-mouse immunoglobulin G (IgG) (H +
L) (A0216, Beyotime Institute of Biotechnology) and developed with an Enhanced
Chemiluminescence Detection Kit (P0018, Beyotime Institute of Biotechnology)
(39 (link)).